/*
 *  FIPS-180-1 compliant SHA-1 implementation
 *
 *  Based on XySSL: Copyright (C) 2006-2008  Christophe Devine
 *
 *  Copyright (C) 2009  Paul Bakker <polarssl_maintainer at polarssl dot org>
 *
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    * Neither the names of PolarSSL or XySSL nor the names of its contributors
 *      may be used to endorse or promote products derived from this software
 *      without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 *  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 *  The SHA-1 standard was published by NIST in 1993.
 *
 *  http://www.itl.nist.gov/fipspubs/fip180-1.htm
 */

#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT && LWIP_INCLUDED_POLARSSL_SHA1

#include "netif/ppp/polarssl/sha1.h"

#include <string.h>

/*
 * 32-bit integer manipulation macros (big endian)
 */
#ifndef GET_ULONG_BE
#define GET_ULONG_BE(n, b, i)                                                  \
  {                                                                            \
    (n) = ((unsigned long)(b)[(i)] << 24) |                                    \
          ((unsigned long)(b)[(i) + 1] << 16) |                                \
          ((unsigned long)(b)[(i) + 2] << 8) | ((unsigned long)(b)[(i) + 3]);  \
  }
#endif

#ifndef PUT_ULONG_BE
#define PUT_ULONG_BE(n, b, i)                                                  \
  {                                                                            \
    (b)[(i)] = (unsigned char)((n) >> 24);                                     \
    (b)[(i) + 1] = (unsigned char)((n) >> 16);                                 \
    (b)[(i) + 2] = (unsigned char)((n) >> 8);                                  \
    (b)[(i) + 3] = (unsigned char)((n));                                       \
  }
#endif

/*
 * SHA-1 context setup
 */
void sha1_starts(sha1_context *ctx) {
  ctx->total[0] = 0;
  ctx->total[1] = 0;

  ctx->state[0] = 0x67452301;
  ctx->state[1] = 0xEFCDAB89;
  ctx->state[2] = 0x98BADCFE;
  ctx->state[3] = 0x10325476;
  ctx->state[4] = 0xC3D2E1F0;
}

static void sha1_process(sha1_context *ctx, const unsigned char data[64]) {
  unsigned long temp, W[16], A, B, C, D, E;

  GET_ULONG_BE(W[0], data, 0);
  GET_ULONG_BE(W[1], data, 4);
  GET_ULONG_BE(W[2], data, 8);
  GET_ULONG_BE(W[3], data, 12);
  GET_ULONG_BE(W[4], data, 16);
  GET_ULONG_BE(W[5], data, 20);
  GET_ULONG_BE(W[6], data, 24);
  GET_ULONG_BE(W[7], data, 28);
  GET_ULONG_BE(W[8], data, 32);
  GET_ULONG_BE(W[9], data, 36);
  GET_ULONG_BE(W[10], data, 40);
  GET_ULONG_BE(W[11], data, 44);
  GET_ULONG_BE(W[12], data, 48);
  GET_ULONG_BE(W[13], data, 52);
  GET_ULONG_BE(W[14], data, 56);
  GET_ULONG_BE(W[15], data, 60);

#define S(x, n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))

#define R(t)                                                                   \
  (temp = W[(t - 3) & 0x0F] ^ W[(t - 8) & 0x0F] ^ W[(t - 14) & 0x0F] ^         \
          W[t & 0x0F],                                                         \
   (W[t & 0x0F] = S(temp, 1)))

#define P(a, b, c, d, e, x)                                                    \
  {                                                                            \
    e += S(a, 5) + F(b, c, d) + K + x;                                         \
    b = S(b, 30);                                                              \
  }

  A = ctx->state[0];
  B = ctx->state[1];
  C = ctx->state[2];
  D = ctx->state[3];
  E = ctx->state[4];

#define F(x, y, z) (z ^ (x & (y ^ z)))
#define K 0x5A827999

  P(A, B, C, D, E, W[0]);
  P(E, A, B, C, D, W[1]);
  P(D, E, A, B, C, W[2]);
  P(C, D, E, A, B, W[3]);
  P(B, C, D, E, A, W[4]);
  P(A, B, C, D, E, W[5]);
  P(E, A, B, C, D, W[6]);
  P(D, E, A, B, C, W[7]);
  P(C, D, E, A, B, W[8]);
  P(B, C, D, E, A, W[9]);
  P(A, B, C, D, E, W[10]);
  P(E, A, B, C, D, W[11]);
  P(D, E, A, B, C, W[12]);
  P(C, D, E, A, B, W[13]);
  P(B, C, D, E, A, W[14]);
  P(A, B, C, D, E, W[15]);
  P(E, A, B, C, D, R(16));
  P(D, E, A, B, C, R(17));
  P(C, D, E, A, B, R(18));
  P(B, C, D, E, A, R(19));

#undef K
#undef F

#define F(x, y, z) (x ^ y ^ z)
#define K 0x6ED9EBA1

  P(A, B, C, D, E, R(20));
  P(E, A, B, C, D, R(21));
  P(D, E, A, B, C, R(22));
  P(C, D, E, A, B, R(23));
  P(B, C, D, E, A, R(24));
  P(A, B, C, D, E, R(25));
  P(E, A, B, C, D, R(26));
  P(D, E, A, B, C, R(27));
  P(C, D, E, A, B, R(28));
  P(B, C, D, E, A, R(29));
  P(A, B, C, D, E, R(30));
  P(E, A, B, C, D, R(31));
  P(D, E, A, B, C, R(32));
  P(C, D, E, A, B, R(33));
  P(B, C, D, E, A, R(34));
  P(A, B, C, D, E, R(35));
  P(E, A, B, C, D, R(36));
  P(D, E, A, B, C, R(37));
  P(C, D, E, A, B, R(38));
  P(B, C, D, E, A, R(39));

#undef K
#undef F

#define F(x, y, z) ((x & y) | (z & (x | y)))
#define K 0x8F1BBCDC

  P(A, B, C, D, E, R(40));
  P(E, A, B, C, D, R(41));
  P(D, E, A, B, C, R(42));
  P(C, D, E, A, B, R(43));
  P(B, C, D, E, A, R(44));
  P(A, B, C, D, E, R(45));
  P(E, A, B, C, D, R(46));
  P(D, E, A, B, C, R(47));
  P(C, D, E, A, B, R(48));
  P(B, C, D, E, A, R(49));
  P(A, B, C, D, E, R(50));
  P(E, A, B, C, D, R(51));
  P(D, E, A, B, C, R(52));
  P(C, D, E, A, B, R(53));
  P(B, C, D, E, A, R(54));
  P(A, B, C, D, E, R(55));
  P(E, A, B, C, D, R(56));
  P(D, E, A, B, C, R(57));
  P(C, D, E, A, B, R(58));
  P(B, C, D, E, A, R(59));

#undef K
#undef F

#define F(x, y, z) (x ^ y ^ z)
#define K 0xCA62C1D6

  P(A, B, C, D, E, R(60));
  P(E, A, B, C, D, R(61));
  P(D, E, A, B, C, R(62));
  P(C, D, E, A, B, R(63));
  P(B, C, D, E, A, R(64));
  P(A, B, C, D, E, R(65));
  P(E, A, B, C, D, R(66));
  P(D, E, A, B, C, R(67));
  P(C, D, E, A, B, R(68));
  P(B, C, D, E, A, R(69));
  P(A, B, C, D, E, R(70));
  P(E, A, B, C, D, R(71));
  P(D, E, A, B, C, R(72));
  P(C, D, E, A, B, R(73));
  P(B, C, D, E, A, R(74));
  P(A, B, C, D, E, R(75));
  P(E, A, B, C, D, R(76));
  P(D, E, A, B, C, R(77));
  P(C, D, E, A, B, R(78));
  P(B, C, D, E, A, R(79));

#undef K
#undef F

  ctx->state[0] += A;
  ctx->state[1] += B;
  ctx->state[2] += C;
  ctx->state[3] += D;
  ctx->state[4] += E;
}

/*
 * SHA-1 process buffer
 */
void sha1_update(sha1_context *ctx, const unsigned char *input, int ilen) {
  int fill;
  unsigned long left;

  if (ilen <= 0)
    return;

  left = ctx->total[0] & 0x3F;
  fill = 64 - left;

  ctx->total[0] += ilen;
  ctx->total[0] &= 0xFFFFFFFF;

  if (ctx->total[0] < (unsigned long)ilen)
    ctx->total[1]++;

  if (left && ilen >= fill) {
    MEMCPY((void *)(ctx->buffer + left), input, fill);
    sha1_process(ctx, ctx->buffer);
    input += fill;
    ilen -= fill;
    left = 0;
  }

  while (ilen >= 64) {
    sha1_process(ctx, input);
    input += 64;
    ilen -= 64;
  }

  if (ilen > 0) {
    MEMCPY((void *)(ctx->buffer + left), input, ilen);
  }
}

static const unsigned char sha1_padding[64] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

/*
 * SHA-1 final digest
 */
void sha1_finish(sha1_context *ctx, unsigned char output[20]) {
  unsigned long last, padn;
  unsigned long high, low;
  unsigned char msglen[8];

  high = (ctx->total[0] >> 29) | (ctx->total[1] << 3);
  low = (ctx->total[0] << 3);

  PUT_ULONG_BE(high, msglen, 0);
  PUT_ULONG_BE(low, msglen, 4);

  last = ctx->total[0] & 0x3F;
  padn = (last < 56) ? (56 - last) : (120 - last);

  sha1_update(ctx, sha1_padding, padn);
  sha1_update(ctx, msglen, 8);

  PUT_ULONG_BE(ctx->state[0], output, 0);
  PUT_ULONG_BE(ctx->state[1], output, 4);
  PUT_ULONG_BE(ctx->state[2], output, 8);
  PUT_ULONG_BE(ctx->state[3], output, 12);
  PUT_ULONG_BE(ctx->state[4], output, 16);
}

/*
 * output = SHA-1( input buffer )
 */
void sha1(unsigned char *input, int ilen, unsigned char output[20]) {
  sha1_context ctx;

  sha1_starts(&ctx);
  sha1_update(&ctx, input, ilen);
  sha1_finish(&ctx, output);
}

#endif /* PPP_SUPPORT && LWIP_INCLUDED_POLARSSL_SHA1 */
